An accumulator conveyor is a conveyor in which objects moved thereon are carried forward, usually in units as on a pallet, to a work or stop position. Subsequent pallets thereupon stop successively awaiting movement of the first stopped unit whereupon all subsequent pallets, then move up to fill the void.
Such devices are best represented by the work of Robert E. Adams in the U.S. Pat. No. 3,513,960 in which conveyor rolls are driven in zones interconnected by link chain and the rolls within each zone are connected to each other for drive of the entire group within the zone. A common motor serves plural zones and a clutch at the commencement of each successive zone engages the chain drive when the load carried by the rolls (as for example a pallet) is depressed starting the driving of all of the rolls in the particular zone. Thus the clutches determine whether or not particular zones function.
In the structure of the present invention each zone is separately powered and the gap between zones is avoided. The driven surface of each zone is a continuous or endless chain transfer system backed by a simple anti-friction roller bed. A staggered overlap of transfer chain in successive zones assures smooth transition of movement between zones and the drive from a single low powered motor advances the work placed on a platform or pallet in each of the zones to a predetermined rest point. The efficiency of the anti-friction chain bed materially reduces power requirements of prior known devices. Common head and tail idling and drive sections between adjacent zone allows the handling of footprints as narrow as 1 inch. The amenability to electrical and electronic sequential control allows a high rate of material transfer due to the zone efficiency reflected in the minimum horsepower requirements and each zone functions as a safety brake in the event of zone malfunction. This also permits precision location of stop and dwell positions as between the zones and makes possible manufacturing procedures or operations at these selected control stop positions. The high efficiency low power provides a self protection feature in each zone so that the motor on overload as by any function generative of a stall condition trips the motor starter heaters. The simplicity of the presently described system allows manual movement of the loads upon disconnect of the input drive or transfer chain and the loads are easily travelled upon the high efficiency transfer bed of each zone. Similarly reversal of the unit is possible to allow clean-out of the structure.
At all times the required zone power is reduced and saves energy and destruction of equipment while the total work achievement accomplishes the accumulator conveyor objectives of material flow.
Accordingly, the principal object of the present invention is to present an accumulating conveyor having plural successive zones in which all zones are provided with separate anti-friction roller beds in support of separate transfer chains that support successive loads and in which each zone is separately powered overlapping the zone directly ahead and directly behind except, of course, for the first zone and the last zone where the overlap occurs in adjacent zones and characteristic motor controls are easily integrated with selected industrial needs.
Another objective is to provide an accumulating conveyor structure in which frictional drag is minimal with attendant lower power requirements and greater flexibility as between zones since individual control of the motors allows selective stopping and starting within selected zones.
Still another object is the provision of an accumulating conveyor on relatively simple foundations easily, adjustable as to height and leveling of zones, and extendable lengthwise by addition of zone modules.
The pallet support of objects moved on the conveyor is adaptable to precision guidance and relative open space beneath the courses permits collateral location of manufacturing and processing equipment all adapted to electronic stop control coordinating selected treatment of work pieces.
In all, those comprehending the present accumulating conveyor will understand the substantial savings in maintenance installation and running costs as well as the achievement of extended flexibility and utility in the new and useful structure.